This is a bug that I reported a long time ago and its still there.
Im loosing my city's stone resources for no reason. Yeah Im not building a wall, not building anything and my storage is not full. For the time that I stayed offline I should had my storage full and lots of stones. However my stones are 180 since yesterday when actually last week was 270. Every time when I change my map mode (home to world and then world to home) I loose some stones. I also notice that this happens when I get attacked, when I do a siege... every time when I change the mode.

Im not sure why this happens, its only with my city when actually I had to have an army carrying stones to keep it safe (and its working). But this is a bad alternative because if I get sieged I wont have stones to use in my bolt throwers. I also notice that before my city loads (when Im comming back to my city mode) I hear some orcs screamming and catapults/bolt throwers shooting. I remember that the firsts quests you have to kill some orcs. Maybe, when Im out of my city they just reappear making my bolt throwers shooting on them (even when they are set to hold fire).

Well this bug is really frustrating for me. Hope you guys fix it.
Thanks